Hydraulic jack



April 12, 1927- J. P. sHEvLlN HYDRAULIC JACK Filed July 14, 1925' .LAW 3 3 m11 1111...?

' has entered into the problem of proper liftv Patented Apr. 12, 1927.

1.624,-15-1 UNITED s TA'resf PATENroFmcE.

JOSEPH SHEVLIN, OF DENVER, COLORADO. ASSIGNOR /T`O ALADDIN HYDRAULIC .JACK COMPANY, 0F DENVER, COLORADO, A CORPORATION 0F COLORADO.

HYDRAULIC JACK.

Application filed .Tuly 14, 1925.

This invention relates to improvements in jacks for automobiles and has reference more particularly to improvements in hydraulic jacks.

The ordinary lifting jacks which are operated by means of a handle that must be moved up and down like a pump handle are open to several serious objections which I will not enumerate in detail. I will, however, call attention to the Jract that the ordinary pleasure car as now constructed has a gas tank, spare tire holder, bumper and sometimes a trunk secured to the rear end.- This makes-it almost impossible to put the ordinary lifting jack in place and to operate the same unless the operator lies full length on the ground. To overcome this difficulty various improved constructions have beeny proposedwhich, however, have not been very extensively adopted. Since the balloon tire has comeint use another element ing jack construction, namely, the fact that when a balloon tire is used the diameters of the wheel rim are greatly reduced with the result that when the tires are deflated the axles are so near the ground that the ordinary jacks cannot be used.

It is the object of this invention, to produce a lifting jack that is short enoughto permit it to be put into place beneath the axles of carshaving balloon tires as well as with those having ordinary -tires and which may be operated by means of a oldable handle of such length that the operator can remain in a comfortable positionwhile using the jack.

The above and other objects that will become apparent as the description proceeds are attained by means of a'construction that I will now describe in detail, reference for this purpose being had to the accompanying drawing in which the preferred embodiment of my invention is shownand in which:

Fig. 1 is a vertical sect-ion taken on line 1&1, Fig. 2;

2 2, Fig. 1;

Fig. 3 is a vertical transverse section of the pump taken on line 38, Figs. 1 and 2v; Fig. l4 is a section taken on line 4 4,

Fig. 3;

Fig. 5 is a Vlongitudinal 'section of the pump lining, and V ci) Fig. 6 isa fragmentary plan view of `the Fig. 2 is a transverse section taken on line A Serial No. 43,499.

handle looking in the direction of the arrow caring. 1.

threaded for the reception of the threaded lower end of the liftingcylinder 3. The raised portion 2 is also provided with a threaded opening 4 for the reception of the threaded projection 5 on the bottom of the pump cylinder 6.. An opening .7 connects the opening 4 with the cylindrical' recess in the manner shown in Fig." 1. casing 8 is secured to the upper surface of the base 1 by means of screws 9 that pass through the flange 10 into the base. IThe-'casing 8'is of such shape that its inner surface fits against the outer edge of the raised portion 2. The top of the casing 8 has a stuiing box 11 through which the tubular piston rod 12 passes. To the lower end of the piston rod, I have secured a metal head 13 of slightly smaller diameter than the interior of the cylinder 3. A threaded lug 14 pro'ects downwardly from the lower side of the ead 13 and has operatively connected therewith a flanged nut V15 by means of which .the leather cup 16 is held in place. Secured to the upper endof the piston rod 12 is a collai' 17 that has two outwardly projecting ears 18 which are perforated for" the recep- 'tion of the pin 19 about whichthe stop plate A .rod 21 which is of the proper 20 pivots. diameter vto iit the interior of the tubular piston above. This rod has a longitudinal groove 22 that is engaged by the screw 23 and which prevents it lfrom rotating with res ect to the 7piston rod. The lower end of t e groove 22 terminates a short distance above the end of the rod 21 so as to provide a "stop -24 which prevents its withdrawal from the piston rod. On the side opposite -from the groove 22 the rod 21, has several spaced notches 25 intovwhich the stop plate may project in the manner shown in full lines in Fig. 1. The upper end of the bar 21v is provided with an upwardly v curved plate 26 whose' upper surface is adapted to` engage the lower surface oii the axle.v The. upper portion of the'cylinder 3 is provided with perforations A of suicient size and number to allow the liquid pumped into said. cylinder to escape into. the chamber'of. the gasing rod 12 is inserted thereinto from` 8, to prevent accident, since 1n the absence of these openings the top of thecasing might be broken if the piston of the lifting cylin-l der -3- should continue its upward movement due to the careless operation .olf the pump.

The pump cylinder 6 has a lining consisting of a tube 27 whose outer diameters Y is such that it fits the cylinder with. a drivof its length\ The threaded ing fit. Before this lining tube -is inserted into thel cylinder, its lower'end is provided with several saw cuts or slots 28 which eX-' tend` upwardly 'a little more than one-third has an axial opening 29 for t of the head 30 of the check valve whose stem 31 extends through an opening in the bottom of the pump cylinder. Operatively associated with the pump cylinder is a' piston or plunger formed on the lower end if the connecting rod 32m The lower end of this rod has `a transverse section resembling a'cross (Fig. 4)l having four .arms 33 that terminates.' short distance below the fiange 34; A cylindrical leather member 35 lsurrounds the cross-like portion rand is held in l place doy a pin or Cotter key 36. A-m-etal washer separates the lower end of the leather member 35 from the cotter key. The leather ring is lof such length that it may reciprocate slightly between the flange and the washer. The leather ring by virtue of the fact thatrit ts closely within the pump cyl- -mder 6, will assume its lowermost position during the `upward'movement of the rod 32, leaving a space below`the ilange 34 and around the cruciformpart of the rod, to

lpermit the liquid to pass from the space above to-.that below the plunger during the l upward movement of the latter. Again for 'the same reason, during the downward move- 4ment of the plunger, the leather ring will move to its uppermost position orinto contact with the flange 34, thus preventing any lliquid `from passing from' the space below the plunerto that above vthe plunger durthe'. ownward movement, of the latter.

in he upper end of therod 32 -is connected ing ..1136 I ave provided.' the bar 44withl @slide-48" tothe crank pin 37 on the end of=th crank arln' 38vhich is integral with the ft 39. It will be noticed that the crank s aft ex- `tends through the-'wallof the 4casing andjisl rotatable inA thestuling box 40. The outer end 4of the crank shaft is squaeand adapted toenter 'i'socket 41 ontlie end Vof the handle. This-:handle comprises two bars* 42 thatare connectedrtotheend of the socket 41 by-means of a pin 43. Another similar bar 44 is pivoted between the other ends of the v.bars-.1.2 b apin 45. VAv short bar 4 6' is pivoted' at 4 vto the bar 44 and serves as ale-' ver bymeans of which lthe shaft 3 9 may given a rotary movement. For thel .purp

preventigthefbas 42 and 44 fonrben about the pivot A45 when they. are

projection 5- e reception that has two projecting,4 side members 49 which en agethe edges of the bars 42 and.

prevent t e parts-from bending.

'When the crank pin 37 is in its uppers v most position, shown dotted'in Fig. 1 the plunger with its leather ring 35 'isin the position with rcsnect to the pump cylinder shownby dotted `lines in Fig. 1, but when the crank pin is in its lowermost position the parts are in the full line position, in which position the check valve in opening 29 is held' open in the manner shown. In' this position the upper edge of the ring 35 is below the upper ends of the slots V28 so that liquid may pass from the interior of lthe cylinder 3 through the passage 7 by the valve head 30 and through the cuts or slots 28 to the upper side of the plunger in the pump arc or suficientlyQtofeauSe the plunger to travel to its lowermost sition. The casing 8 is rovided with an opening in its top that4 is c osed by a plug 50. This opening is employed for filling the casing with liquid. The liquid usedv may beWater, oil. or a mix ture' of glycerine and alcohol or`any other liquid. that is lsuitable for this purpose.V The casing can be lled with liquid toa point slightly above the topy of the cylinder 3 as the liquid space is constantat all positions of the piston and plunger. The liquid within the ,casing is not under pressure at any.

time as the pressure is confined to the space below the piston and pump plunger.

' The operation of my device is as follows'.

Let us assume that the parts are in the positionshown in Fig. 1. The operator-grasps thebit'i46 and rotates the shaft'39 one-half a turn thereby bringing the crank arm to dotted=line position. Whentheplunger in the pump cylinder .moves upwardly liquid will pass from the 'top to ,the lower side thereof, travelingthrough the space'below th`e flange 34/ and around the crucifofgmpart of the rfid 32 as heretofore exp ained.

Whenrtliel plunger is again moved downwardly it will force liquid past the check .lvalve'through the passage 7 andl into the cylinder 3 thereby moving the piston rod l2 'v pwardly. The check valve willpreventrthe iquid'from returning into .the pump 'as the j lunger is again moved upwardly. In this anner the piston rod 12 is gradually ex- ,tnded When the load istogbe lowered the cylinders being in open communication `above their pistons with the chamber of the toCthe-fact that thel by-pass is opened by a slight eXtra rotation of the shaft 39 which makes it possible to release the jack without removing the handle from the end of the shaft, as heretofore explained.

Having now described my invention what I claim' as new is:

, 1. A hydraulic jack comprising lifting and pump cylinders having associated pistons and piston rods, and an operative connection between the cylinders for the transfer of liquid in the operation of the jack, Aand a tight casingenclosing both cylinders and forming a chamber for the liquid, the

casing.

2. A hydraulic jack comprising lifting and pump cylinders having associated pistons-and piston rods, and an operative conncctionbetween the cylinders for the transfer of liquid in the operation of the jack, andy a tight casing` enclosing the cylinders and forming a chamber for the liquid, the cylinders being openat the Ytopfor the free circulation of liquidf 3. A hydraulic jack cqmprising lifting .and pump cylinders havingassociated pis- Atons arid piston rods, and, an operative connection between the cylinders for the transfer of liquid in the operation of the ljack,

the cross-sectional area of fthe pump cylinder being less than that of the lifting cylinder, and a tight casing enclosing theisaid cylinders and forming achamberv for the lliquid, the cylinders being open at the top for the free circulation of liquid by displacement during the operation of thejack.

4. A` hydraulic jack comprising lifting and. pump cylinders having associated pisf.'

tonsand piston rods, and an operative connection betweenthe cylindersjfor the transfer of liquid in the operation ofthe jack, `and a tight casing enclosing the cylinders and forming a chamber for the liquid, the

cylinders being in .open coml'nuni'cation a ove 'their pistons with the .ch ber ofthe casing, the upper portion of the hftingv cyly indenhaving openings to allow the liquid ofthe cylinder below its piston to pass into the chamber of the casing to prevent the' fpiston from engaging the top of the casing during its upward travel.

5. A structure of the class described comprising lifting Lfand pump cylinders and as- Sociated pistons and piston rods, the said .cylinders being operatively connected at'the bottom for thepassage of liquidv for load pump piston being operatively connected:

through an'ope'ning in the casing for maf nipul'atlng purposes.

6. A hydraulic jack comprising a'base,

lifting and pump cylinders mounted thercl' 0n and provided with associated pistons and piston rods, the two cylinders being connected by a check-valve-controlled duct for the VVpassage of liquidfrom the pump cylinder to the lifting cylinder below the piston of the latta-,the pump piston including a ring litting closely within its cylinder and having 'a limited reciprocable movement between uppercand lower stops on the rod which isI open within the ring for the passage of liquid, the lower part of the wall "of the pump cylinder having shallow grooves whose Vertical length is somewhat greater than the vertical length of the piston ring to permit the passage ofliquid from a. position below to a position above the piston for load releasing purposes whenever the piston is in its lowermostposition, the check valve being arranged to be heldJpfniby the pump pis-A ton to cooperate with thesaid grooves for the return of the liquid from the lifting cylinder to the pump cylinder. l

.` 7./A. hydraulic jack comprising,`in combination, a base member, a casing members' open' at oneend and adapted to`be secured to the base in such a manner that the base 'forms a closure for the open end whereby u enclosed within said casing and having their upper ends spaced from the casing, a communicating paszage between said cylinders, 'a pump piston in the vpump cylinder, a

plunger in the plunger cylinder and means extending through the 'casing for operating the pump piston. ,f

' 8. A hydraulic jack comprising, in combination, a base member, a casing member open at one end and adapted to be secured to the bas in such a manner that the baseforms acl@ re ifor" the open end whereby a closed reso `voir is formed for the reception of a liquid, a plunger cylinder securedat its lower end to said base, a p ump cylinder secured at .its lower end to said base, said plunger and pump cylinders being entirely enclosed withinsa'id casing andhaving their` upper ends spaced from the casing, a communicating passage between said cylinders, a pump piston in the pump cylinder, a

plunger in the plunger cylinder',V a plunger.y

rod connected with thev plunger piston and V extending` outwardly through the casing,

said r d .being of a smaller diameter than the interior of the plunger cylinder so as to v plunger is below the upper end'of .the cyl- *I inder, 'und an perative connection between theoutside of the `casing and thepump pis'- 10 ton whereby 'thelatter ma be reciprocated for the purposof transferring liquid to the -plunger cylinder. 

